An X-Y stage apparatus (hereinafter, referred to as a stage apparatus) is an essential equipment for transferring, or moving, a workpiece during a precision manufacturing process. Since the precision manufacturing can be successfully performed only when the transfer of the workpiece is strictly controlled, research for improving the performance of the stage apparatus has been concentrated on a guiding apparatus and a driving method therefor. Also, difficulties in the development and manufacturing of a precision guide or bearing are other reasons why the research is concentrated thereon.
FIG. 1 is a perspective view of a conventional stage apparatus and FIG. 2 is a diagram illustrating a manufacturing process consisting of an exposing process using the stage apparatus shown in FIG. 1. In the example of FIGS. 1 and 2, a workpiece is an exposing plate P of a liquid crystal display (LCD) device. The conventional stage apparatus is transferred straightly along X- and Y-axes on a horizontal surface. In FIG. 1, the exposing plate P is placed on a stage 11. Here, "L" represents the lengths of the exposing plate P in the horizontal and vertical directions. Also, a portion enclosed by dotted lines represents an area (m.times.m) which can be exposed through only one irradiation process. Thus, if it is intended to expose the whole area of the exposing plate P of the LCD, the stage 11 should move in the X- and Y-directions as much as (L-m) as shown in FIG. 2.
In the above-described conventional stage apparatus, if a workpiece to be exposed is large, the stage apparatus must be enlarged according to the size of the workpiece. Thus, it is inevitable to replace the stage apparatus with a more suitable one. However, there are difficulties and high costs associated with manufacturing the large stage apparatus. Therefore, a stage apparatus which is adaptive for changes in the size of the workpiece is desirable.